1. Field
The present disclosure relates generally to inspection systems and, in particular, to nondestructive inspection systems. Still more particularly, the present disclosure relates to a method and apparatus for nondestructively inspecting an object using acousto-optics to determine whether a feature of interest is present in the object.
2. Background
Nondestructive inspection (NDI) systems are oftentimes used to inspect different types of objects, including composite structures. Nondestructive inspection systems allow an object to be inspected without affecting the object in an undesired manner. In some cases, a nondestructive system may also be referred to as a nondestructive testing (NDT) system or a nondestructive evaluation (NDE) system.
A variety of nondestructive inspection methods are currently available for use with composite structures. However, some of these currently available methods are slower and more expensive than desired. Further, some of these currently available methods may require an expert in nondestructive inspection to perform the nondestructive inspection.
For example, some currently available ultrasonic nondestructive inspection methods, including ultrasonic pulse echo methods, may be more expensive than desired, may be slow to run, may require an expert to perform the inspection, or some combination thereof. A low-frequency bond testing method may be used, but this method may also be slower than desired in some cases. Further, an expert in nondestructive inspection may also be needed to perform low-frequency bond testing.
While faster methods such as laser shearography and infrared thermography able to provide results in substantially real-time are known, these may be prohibitively expensive. Providing results in substantially “real-time” means providing results without significant delay between the performance of the inspection of an object and the generation of the results. These results may take the form of, for example, images, that provide visual indications of whether undesired features of interest are present in an object. The results may then be analyzed or interpreted by, for example, a human operator at the same time at which the results are generated or at some later time. Further, infrared thermography may be unable to detect certain types of features, such as “kissing” bonds. A “kissing” bond may be a bond between two parts that have been positioned and coupled relative to each other with substantially no gap or space present between these parts. This coupling may have been performed using, for example, an adhesive. This type of bond may have reduced strength and, in some cases, substantially zero strength.
Thus, these currently available nondestructive inspection methods may be unable to provide the type of fast, simple, and inexpensive inspection that may be useful in certain situations. Therefore, it would be desirable to have a method and apparatus for performing nondestructive inspection that take into account at least some of the issues discussed above, as well as other possible issues.